Adjunct Professor of Physics
Dr. Everitt is one of the Army's chief scientists. He works at the Army's Aviation and Missile RD&E Center at Redstone Arsenal, AL. Through his adjunct appointment in the Duke Physics Department, he leads an active experimental research group in condensed matter physics, nanophotonics, molecular physics, and novel terahertz imaging with colleagues on campus and through an international network of collaborators. Four principal research areas are being pursued:
1) Ultrafast Spectroscopy. This effort concentrates on the ultrafast spectroscopic characterization of wide bandgap semiconductor heterostructures and nanostructures. We use independently tunable pump and probe wavelengths that span the ultraviolet-visible-infrared regions from 200 nm to 12 microns with pulses shorter than 150 fs. The objective is to mapout and control carrier, exciton, and phonon transport and relaxation pathways in metal oxide and III-N semiconductors, sometimes doped with rare-earth atoms, using quantum efficiency, cw and time-resolved photoluminescence and differential transmission measurements. Areas of recent interest include characterization of efficient phosphorescence in sulfur-doped ZnO, carrier dynamics in III-N epilayers and multiple quantum wells, and characterization of radiative and nonradiative recombination of rare earth dopants in wide bandgap semiconductor hosts.
2) Ultraviolet Nanoplasmonics. Using metal nanoparticles to concentrate electromagnetic fields locally is an area of active research, most of which concentrates on using Au or Ag in the visible or near infrared spectral regions. Neither metal works in the ultraviolet, but there are significant advantages of extending plasmonics into the ultraviolet, including enhanced Raman cross sections, accelerated photo-degradation of toxins, and accelerated excitonic recombination. In partnership with Profs. April Brown (Duke ECE), Naomi Halas (Rice Univ.), Fernando Moreno (Univ. Cantabria), and others, we have been identifying and exploring new nanostructured metals including gallium and aluminum for ultraviolet plasmonics. We have recently demonstrated accelerated emission rates and surface enhanced Raman spectra in the ultraviolet.
3) Molecular Physics. The longest research effort involves the use of molecular rotational spectroscopy and time-resolved techniques to investigate molecular collision dynamics. These studies will help us develop more efficient terahertz sources, detect and identify clouds of trace gases, and understand nonequilibrium atmospheres and interstellar media. In collaboration with Prof. Frank De Lucia of Ohio State Univ., Dr. Everitt was the first to map out the complete rotational and vibrational energy transfer map of methyl fluoride, leading to the demonstration of a compact, tunable, coherent source of terahertz radiation for use in ground-based spectroscopy and astronomical observation. This double resonance technique has now been adapted as a new means for remotely identifying the constituents of a trace gas cloud at distances up to 1 km.
4) Terahertz Imaging. This newest activity uses powerful, cw, tunable millimeter- and submillimeter-wave sources to adapt various coherent imaging techniques to the terahertz spectral region. Interferometry, digital holography, tomography, synthetic aperture RADAR, ISAR, ellipsometry, and polarimetry are all explored to develop practical tools for non-destructive measurements of visually opaque materials. The lab contains a unique combination of tunable sources, Schottky diode detectors, heterodyne receivers, and bolometers, plus a one-of-a-kind THz beam characterization and imaging instrument. The lab also explores ways of optimizing and accelerating these slow imaging methodologies using digital reconstruction and compressive sampling techniques pioneered by on-campus collaborator Prof. David Brady and novel beam forming metamaterials with Prof. David Smith.
Kong, W., et al. “UVB-emitting InAlGaN multiple quantum well synthesized using plasma-assisted molecular beam epitaxy.” Aip Advances, vol. 7, no. 3, Mar. 2017. Scopus, doi:10.1063/1.4973637. Full Text
Zhang, Xiao, et al. “Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation..” Nature Communications, vol. 8, Feb. 2017. Epmc, doi:10.1038/ncomms14542. Full Text Open Access Copy
Liu, J., and H. Everitt. “Light-driven reaction converts carbon-dioxide into fuel.” Chemical Engineering World, vol. 52, no. 2, Feb. 2017.
Zhu, Ruoyu, et al. “Compressive sensing and adaptive sampling applied to millimeter wave inverse synthetic aperture imaging..” Optics Express, vol. 25, no. 3, Feb. 2017, pp. 2270–84. Epmc, doi:10.1364/oe.25.002270. Full Text Open Access Copy
Simmons, J. G., et al. “How sulfidation of ZnO powders enhances visible fluorescence.” Journal of Materials Chemistry C, vol. 5, no. 41, Jan. 2017, pp. 10770–76. Scopus, doi:10.1039/c7tc04047d. Full Text
Gutierrez, Yael, et al. “How an oxide shell affects the ultraviolet plasmonic behavior of Ga, Mg, and Al nanostructures..” Optics Express, vol. 24, no. 18, Sept. 2016, pp. 20621–31. Epmc, doi:10.1364/oe.24.020621. Full Text Open Access Copy
Akyildiz, Halil I., et al. “Photoluminescence Mechanism and Photocatalytic Activity of Organic-Inorganic Hybrid Materials Formed by Sequential Vapor Infiltration..” Langmuir : The Acs Journal of Surfaces and Colloids, vol. 32, no. 17, May 2016, pp. 4289–96. Epmc, doi:10.1021/acs.langmuir.6b00285. Full Text Open Access Copy
Alabastri, Alessandro, et al. “Extraordinary Light-Induced Local Angular Momentum near Metallic Nanoparticles..” Acs Nano, vol. 10, no. 4, Apr. 2016, pp. 4835–46. Epmc, doi:10.1021/acsnano.6b01851. Full Text Open Access Copy
Reish, M. E., et al. “How Annealing and Charge Scavengers Affect Visible Emission from ZnO Nanocrystals.” Journal of Physical Chemistry C, vol. 120, no. 9, Mar. 2016, pp. 5108–13. Scopus, doi:10.1021/acs.jpcc.5b12094. Full Text Open Access Copy
Hokmabadi, M. P., et al. “Polarization controllable THz stereometamaterial absorber.” International Conference on Infrared, Millimeter, and Terahertz Waves, Irmmw Thz, 2014. Scopus, doi:10.1109/IRMMW-THz.2014.6956184. Full Text
Roberts, A., et al. “Probing electron-phonon interactions at the saddle point in graphene.” Optics Infobase Conference Papers, 2014.
Butler, L., et al. “Design, simulation, and characterization of THz metamaterial absorber.” Proceedings of Spie the International Society for Optical Engineering, vol. 8363, 2012. Scopus, doi:10.1117/12.919625. Full Text
Baughman, W. E., et al. “Comparative reconstructions of THz spectroscopic imaging for non-destructive testing and biomedical imaging.” Proceedings of Spie the International Society for Optical Engineering, vol. 8363, 2012. Scopus, doi:10.1117/12.919627. Full Text
Everitt, H. “Coherent terahertz holographic and tomographic imaging.” Optics Infobase Conference Papers, 2012.
D’Aguanno, G., et al. “UV-SERS assisted by nano-focusing in plasmonic gratings with tapered slits.” Frontiers in Optics, Fio 2012, 2012.
Heimbeck, M. S., and H. O. Everitt. “Polarization sensitive terahertz digital holography.” Frontiers in Optics, Fio 2012, 2012.
Kumar, Sushil. “Operation of terahertz quantum cascade lasers above 160 K covering a frequency range of 2-4 THz.” Terahertz Emitters, Receivers, and Applications Iii, SPIE, 2012. Crossref, doi:10.1117/12.929760. Full Text
Halbur, Jonathan, et al. “Enabling of nanoparticle application and function on the surface of fibrous textiles by atomic layer deposition.” Abstracts of Papers of the American Chemical Society, vol. 243, AMER CHEMICAL SOC, 2012.
Phillips, D. J., et al. “Infrared/terahertz double resonance spectroscopy remote sensing.” Irmmw Thz 2011 36th International Conference on Infrared, Millimeter, and Terahertz Waves, 2011. Scopus, doi:10.1109/irmmw-THz.2011.6105115. Full Text